


It Was Pouring Outside

by Channelei



Category: Haikyuu!!
Genre: Alternate Universe, Alternate Universe - Soulmates, AtsuKita, Best Friends, Childhood Friends, Childhood Sweethearts, F/M, Fluff, Freeform, Friends to Lovers, Haikyuu!! Manga Spoilers, High School, Inarizaki, Jealous Miya Osamu, Miya Atsumu is a Little Shit, One Shot, Pining, Pro Volleyball Player Miya Atsumu, Reader-Insert, Requited Love, Requited Unrequited Love, Short One Shot, Soulmates, Unrequited Crush, Unrequited Love, Volleyball
Language: English
Status: Completed
Published: 2020-08-17
Updated: 2020-08-17
Packaged: 2021-03-06 02:07:28
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 2,956
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25905577
Author URL: https://archiveofourown.org/users/Channelei/pseuds/Channelei
Summary: Atsumu isn't your soulmate but Osamu is right there to pick up the pieces. Just like always.Finding your soulmate has never been so complicated, especially when identical twins with identical marks get mixed into the equation.Soulmate AU: You and your soulmate have matching marks on your wrists.[miya osamu x reader]
Relationships: Kita Shinsuke/Miya Atsumu, Miya Atsumu/Reader, Miya Osamu/Reader
Comments: 5
Kudos: 195





	It Was Pouring Outside

They say that _"even if you take down Miya Atsumu, his twin Osamu will be right there to pick up the slack."_

Miya Atsumu is a loudmouth and a prick, but that's old news to anyone who has spent time with him. Regardless, he and his brother were easy to befriend at the young age of 4 when all three of you were too aloof to have a care in the world. But that doesn't mean there weren't any bumps in the road.

When he was a child he liked to pull on your pigtails and call you names mindlessly, soon expanding his vocabulary once he and Osamu 'accidentally' stumbled across a website chock-full of vulgar words.

It was a daily ritual between you two; a constant battle over who could get the last jab in and leave the other person feeling miserable. Some nights you would go home - to the quaint little house situated a few doors down from the Miya residence - and cry your eyes out. It was those nights that Atsumu would lock himself in his room absolutely seething and fuming, thrashing his arms about and landing punch after punch into the fluff of his pillow.

He would cuss and yell until his lungs hurt, all because of some childish bickering between you and him that would leave a bitter taste at the back of his throat. It made him especially upset when he knew he had made you cry, because it was then that Osamu was given the task of going over to check up on you.

Slowly, shyly even, you would open the front door an hour after sprinting home to see Osamu standing there. Despite the fact that neither of the twins had dyed their hair yet, it was easy for you to decipher who was who. After all Osamu is the calm twin, the one to pick up the slack, the one to bandage up all of Atsumu's wrongdoings and kiss the wounds better.

He would apologize profusely to you until his tongue got caught between his canines. And while you felt pretty bad for upsetting Atsumu, the hurt you felt was nothing compared to the heart wrenching scene of Osamu standing in his pyjamas in the cold at 9pm giving apology after empty apology. All for Atsumu. His stupid, _stupid_ brother.

It was another night like this when Osamu finally let out an exhausted sigh and stomped into Atsumu's room. At 10 years old, the younger Miya had already grown tired of this fierce tug of war between his brother and their best friend.

"Shuddup already, wouldja?" he had told his brother off who was sitting on his bed in confusion. "Quit bein' so mean to (f/n)-chan. You're a real asshole, ya know that?"

It wasn't until junior high that things took a turn.

By that point, you'd been friends with the twins for nearly ten years of your lifespan. The thickened skin earned from years of screaming and yelling at Atsumu only grew when he would continue pestering you. You and him were both grossly aware of the marks on your arms. They permanently etched into your flesh the day you turned 12. No one talked about them. No one dared to bring them up. Not even Osamu, who had the same mark grafted into his skin, wanted to acknowledge the existence of the binding graffiti.

Why? Because ~~he was afraid that you were meant for Atsumu~~ it would make things complicated for his two best friends in the whole world. It was easier for him to keep his lips sealed rather than actively stir up problems within the little world the three of you had created for yourselves. And if that meant being in love with you (whatever love a 14 year old boy can feel) and still not saying a peep? So be it.

There was no doubt that Osamu had seen the shared glances between you and his brother. Or the way your fingers would linger against each other when they happened to brush. Or even the subtle flirtatious suggestions Atsumu would give with the wiggle of his eyebrows every now and then.

He ignored the twinge of jealousy he would feel whenever you and Atsumu would be genuinely enjoying each other's presence rather than arguing. And he definitely tried to stop dwelling on the reoccurring voice in his head screaming _'If I had known identical twins meant identical marks I would have eaten you in the womb!'_. 

The Miya twins immersed themselves into the volleyball world, soon becoming a common conversation topic around the small prefecture of Hyogo. They were practically celebrities. Being caught in the crossfire of the complicated relationship between his brother and his best friend, he found that it was easy to throw himself into the sport and nothing more.

So, while Osamu had less of a fire burning within him to play volleyball than his brother, they both completely dominated any other duo in their prefecture and climbed to the top of the popularity food chain. They were sharks, lions, predatory vultures that were unreachable by the mice and pigs at the bottom. Osamu felt a little relieved that he and Atsumu had found their high ground in social ranks. The last thing he wanted was to be called average, because being average means being normal, and being normal means being boring.

And he and Atsumu were anything but boring.

Osamu liked having you by their side. He liked seeing you at every game they played, he adored the way you would force him to lean down a bit so you could reach the top of his head to ruffle his sweaty locks. He especially enjoyed that he was the one who earned this kind of special treatment from you and not Atsumu because, according to you, Atsumu was _'too much of a dick to earn a good head pat'_.

Is that why it hurt so much when he barged into Atsumu's room one dreary evening only to see the two of you pressing your wrists together? He nearly dropped his bowl of ice cream at the sight of your concentrated faces, mouth slightly agape and jaw ajar. "What... What the hell are you guys doin'?" was the only thing he could say.

It was a lengthy explanation that he hardly remembers to this day. Apparently you'd wanted to see if pressing the marks together would elicit any kind of event to happen. He knew then that the three of you would never be the same. He was being forcefully dragged out of the comfort of what he called 'home'; something built over a decade by you triad of goofballs. And it was _terrifying_ to Osamu to suddenly feel like he was being ejected from the bubble that had always included him in it.

"I like ya, [name]," Atsumu openly admitted even with his brother standing right there in the frame of his bedroom door. "A lot. And well, the marks speak for themselves don't they?"

Osamu wanted to scream, to yell, to grab you by the face and cry in your face that 'I have the same mark! Please give me a chance, too!', but by the completely elated look on your face he knew that he had lost a fight that never even happened. With the rug pulled out from under his own two feet, all he could do was stand and stare while you and Atsumu engaged in a tight embrace that left him feeling hollow. 

It no longer felt like you and Atsumu and Osamu. It felt like you'd scratched his name from the list and made the trio a duo. He so badly wanted to speak up and say something but his words felt like they were coming out of his mouth as tangible objects that gagged him on their way up. So the best he could do was muster up a smile and give a soft, halfhearted "congratulations" through his teeth. 

He couldn't bear seeing the two of you together. Atsumu was right, the marks spoke for themselves. And while he knew from personal experience that there was a lot of arguing and teasing in your relationship, there was also an unmistakeable chemistry. All your problems together were just background noise in the wake of your adoration for one another. Osamu wanted the earth to open up under him and swallow him whole every time he would catch the fondness in your eyes, or when you would come running into his arms when Atsumu made you cry. He convinced himself that you were only projecting the twins as the same entity - that just because they looked alike they were the same. 

Osamu was an ignorant child, a little boy who had no idea what to do with whatever feelings he was harbouring toward his twin brother's girlfriend. He wanted to believe that you were being selfish, that you were trying to search for pieces of Atsumu while in his arms. But he knew this wasn't true, he knew that you were the last person on this planet who would ever do that. And that made the dull ache in his heart all the more painful. 

The day after a heart-shattering argument with Atsumu when you'd shown up in his room wailing and clutching onto him, Osamu came to school sporting a fancy new haircut. Silver suited him well, cool and steely and incredibly stylish matching his eyes. You weren't surprised. You knew it would happen one day - that the twins would want to separate from being one homogenous mixture of cuss words and anger issues and become individual teens. Atsumu wasn't far behind him having bleached, brassy blond hair and a nastier attitude than usual. 

High school was a whole other level of drama. You had no idea that the Miya twins were so popular that they would have their own fan groups formed by the end of the first week. Atsumu was totally engaged in the popularity, talking to every girl (and boy, you noted) that he had a chance to chat up and often ditching you and Osamu to hang out with others. Surprisingly the relationship between you and Atsumu settled back to normal not long after breaking up. It was one of those cliche mutual breakups that leave no heartbreak lingering in either heart. 

Curiously, Osamu found himself not reminding you that there was a mark identical to yours on his own wrist. He would wait, even if it meant silencing himself for years, until you were ready to talk about it. Along the way to the end of school you and him picked up a boy named Suna and welcomed him into your bubble. When first year ended Atsumu practically came crawling back and the feeling of home was reinforced tenfold. 

After a complicated two years of messy feelings and relationships, everything rewinded back into three young teens who would do anything in the world for each other. And with Suna now included, the quadruplet felt like the rulers of the world. Osamu no longer felt that twitch of annoyance he usually felt when you and Atsumu would give each other fond looks after an argument because he was absolutely certain that you were not soulmates. Instead he often found himself staring lovingly at you as you gave quick witted insults and jabs while Suna recorded it all for blackmail. 

He couldn't help but feel like he was staring at the entire universe, at all the stars and planets as they align, at every event horizon and supernova. Being in love with you since he was just a small boy was electrifying. Hard, yes, but incredibly satisfying because he knew that you were meant to be. 

You and him were both unsurprised when you turned the corner one cold afternoon to see none other than Kita Shinsuke in the arms of Atsumu. It was an endearing sight. Kita was (and still is) shorter than Atsumu, so his head was buried into the crook of the blond's neck and was being peppered with kisses to the top of his head in return. Atsumu was animatedly embarrassed to be caught in such an intimate moment with his captain, his face flushed a dark hue of crimson and his hands flailed around helplessly. Kita did nothing but chuckle at his actions before flashing his wrist in the air to reveal a familiar mark. 

It was the same as the one on the wrist of the three other people in the room. 

The consensus was pretty unanimous when Kita started joining the group during lunch: they were perfect for each other. On one hand, the captain was so patient but stern that it tamed whatever teenage rebellion phase Atsumu was going through. On the other hand, Atsumu was helping Kita lighten up a little bit, and the silver-haired "oh-so-stoic Mr. Perfect no gaps" Kita Shinsuke was beginning to smile more and more as the days went on. 

When it was practically confirmed which pair of marks was meant for which couple, Osamu finally allowed himself to indulge in your presence more than he did as children. He enjoyed small intimate gestures like stealing forehead kisses on the walks home or holding your hands under the lunch table away from everyone's eyes. He especially liked the feeling of your body curled up against his whenever you came for sleepovers and the way you would run up to him before anyone else after they won a good game. 

Neither of you explicitly brought it up but you both knew you were soulmates just from that tingling sensation you got from pressing your marks together. One of the main reasons that you hadn't started dating was because your future plans were jarringly different. As if there was a fork in the road, the friend group you'd forged over 13 years was going to be taking all kinds of different paths. While Atsumu and Suna were aiming for pro teams, Osamu and Kita were planning on staying behind in Hyogo to focus on their own passions. And while you wanted to stay with them, you knew that there was a calling for you in Tokyo that you couldn't ignore. 

So on the last day of a particularly hot summer, you embraced the boy you loved for so many years and hopped onto the train with Atsumu and Suna on your heels. Leaving Osamu and watching him disappear into the distance in the morning fog, you couldn't help but feel a little bit lost. After all, it was the first time you'd ever been away from the man. And even with his rambunctious twin brother joining you in the big city, you no longer wanted to waste time tiptoeing around the subject of being together. You called him that same night, sobbing and rambling on and on over the phone about how you loved him and how you wanted to be in his arms. Osamu bought his train ticket the next morning. 

When he showed up at your door, it was pouring outside. 

His hair colour was fading back into its natural dark brown, a shade that you remembered fondly as a child. His locks were matted against his forehead and he was panting from sprinting down the streets to your school dormitory. He smelled of morning rain and sweat and cologne. He smelled like childhood. Like Hyogo. Like home.

The young man was quick to engulf you in his arms, not caring to listen to the protests you gave about your dampening clothes. The look of longing and love in Osamu's eyes was enough to make you weak in the knees and the burn of your marks smooshed together made the moment all the more memorable. The first words out of his mouth were "I love you," followed by a tangent of how he'd wanted you to be his since you were just 6 years old. 

The gravity of his words was enough to paralyze your legs and make you tumble to the ground of your room. He followed suite, wrapping his arms around you as he doused your face in kisses and whispered affectionate words into your ear. Then, just as he'd dreamed of doing for so long, he grabbed your face and pressed your lips against each other in a fashion similar to the way you would your soulmate marks. It was a short kiss, sweet and loving like every other action Osamu has ever done with you. 

You can't help but let your mind drift back to when the two of you were just innocent little kids fated to fall in love and bound by an identical marking yet to appear. Back to sleepovers full of scheming and telling scary stories to prank Aran. Back to that little boy who would show up at your childhood home to make the hurting go away whenever his idiot brother would yell at you. 

The rain pelting against the window diminuendoed into a soft shower that filled the room with comforting white noise. As the water from his clothes soaked into yours, you wanted nothing more than to freeze time and capture this moment forever. This was the road to finally being with Miya Osamu, the quiet twin, the one to pick up the slack, the one to resuscitate whatever casualty Miya Atsumu leaves in his wake. 

And after 7 hard years of vigorous studying, working, opening an onigiri shop and celebrating with you over facetime, Osamu is just about ready to give you the Miya last name, just as you'd joked about when you were stupid kids who had no idea what love was.

**Author's Note:**

> This is the first time I've written a soulmate AU so hopefully this is alright!!  
> I love the Miya boys so much and AtsuKita is one of my OTP so I just had to sneak it in LOL
> 
> Honestly just stan Inraizaki, they're all so precious
> 
> I hope you enjoyed!
> 
> Link to my Wattpad: [Channelei](https://www.wattpad.com/user/Channelei)


End file.
